zakk Wylde son of screamer/sd-1 ??

[gazza]

Hi All,

I really liked the MSR Zakk Wylde overdrive that i demo'd this week.

but since I can build (and tweak) something similar for about 30% of the cost........ the diy bug has hit

my plan is to start with the 'Son of Screamer' schematic.  I am attempting to transplant the tone control directly from the boss SD-1 schematic.

Any guideance on this anyone ?  

I hope to put a bass boost switch on the thing that will change the capacitor (c2 SoS schemo) that goes to 4.5V from the feedback loop, and I might add a clipping diode selector switch too (both non-symetrical, but different forward voltage drops. Ge and LED combos maybe).  It seems that it might be good to keep a capacitor in the feedback loop for stability - will the 47pF wreak things ? would it be better as 10pF ?

I'll use a proper bypass switch (millenium fet trick).

Will this get me close ???  

what I've picked up from other posts is that I should,

i) try to boost the lows a bit by upping the caps of the low pass filters
ii) use the SD-1 tone control and not the TS one
iii) maybe use the SD-1 feedback loop values.

any HELP and ADVICE greatfully received.

Seasons Greatings

Gareth.

[vanhansen]

I don't have any tips really.  From my understanding of the ZW44 is it's a modded SD-1 basically.  More lows, more gain.  There's probably a few other tweaks in there but I haven't seen the guts of it to know.

I like your idea.  I modded my SD-1 and have it sounding pretty darn sweet.  Haven't demo'd the ZW44 yet but would like to.

[cd]

The ZW44 is an SD-1 with no output buffer, with a slightly narrower range of the tone control.  Oh, and the chip is different (surface mount) but if you're building your own, you're going to use a socket and swap to your heart's content.

[jimbob]

why hasnt anyone rev this one yet? or created a schematic?

[guitarmonky55]

ive been looking into the same exact thing,   im a HUGE zakk fan.  once i get my new marshall head here(jcm800) im looking to build a good overdrive to do a similar thing to what he does.  i actually was planning on using a modified tubescreamer circuit in a hammond box and giving it the cool bullseye paintjob too :twisted:

i would really love to hear about any developments with this, ill definitely build it if it goes through.

[jimbob]

Good idea! I think ill do the same as far as the Bullseye goes. Why not? :twisted:

[cd]

why hasnt anyone rev this one yet? or created a schematic?

There's really nothing to rev, it's an SD-1.  IIRC the chip is a 33178.

[rama claproth]

If you have an SD1 boss pedal, you can convert it into MXR ZW44 specs!

1. Remove one leg of the resistor 33K (R5) that goes with 4K7 (R6) and connect to the diode's leg (D1) that goes to pin 7 at the opamp chip. Remove yellow wire # 4 at the PCB and also remove red wire # 2. Connect yellow wire at # 2, # 4 stays EMPTY. Connect red wire to where the 33K resistor's leg USED to stay that connects with the resistor 4K7 at R6, now this automatically goes to the opamp at pin 6.

2. Replace C4 with a 0.047uF capacitor.

3. Replace C5 with a 0.047uF capacitor.

4. Replace R3 with a 22K resistor.

5. Replace C7 with a 3.3uF capacitor.

6. Remove Q6, R15, R16, R17, and C10. These NO NEED jumpers. The white wire # 12 at the PCB must be removed and has to be connected into the hole where the base pin of Q6 used to stay.

7. Remove brown wire # 1 at the PCB and connect into ground.

8. Change Q5 with MPSA14 transistor. This is OPTIONAL.

DONE!